This invention relates in general to electromechanical digital media drives, such as hard disk drives, floppy disk drives, Zip(trademark) drives, CD-ROM drives, and DVD-ROM drives. More specifically, the invention relates to devices and methods for mounting and damping vibrations of electromechanical digital media drives in computers and other mounting locations.
Hard disk drives typically include a group of one or more stacked platters that spin past movable read/write heads at tremendous speeds and within very close tolerances. Each of the platters stores data in a series of concentric regions referred to as xe2x80x9ctracks.xe2x80x9d When reading data to or writing data from the platters, the read/write heads rapidly move from one track to the next as they read or write the data. CD and DVD drives also have a platter, the CD or DVD, that rotates past a movable lens assembly.
As digital media drive, including CD, DVD, and hard disk drives, platters spin, and their head or lens assemblies move, they inevitably vibrate. Vibrations from these drives can couple into other drives of the system if they are not adequately damped. There are additional vibration sources in typical computer systems, including among other sources vibrations induced by user""s fingers on keyboards (especially keyboards of notebook computers), loudspeakers, and cooling devices such as fans and blowers that may vibrate as they spin. Computer systems may also be subject to vibrations from other external sources.
Vibrations can sometimes cause the read/write heads in a hard disk drive to miss the track they are supposed to read data from or write data to. This is referred to as a xe2x80x9ctracking error,xe2x80x9d and it may result in corrupted data. These vibrations can be introduced by vibrations or shock from outside the drive, or by internal rotational vibrations induced by the spinning platters. Although some internal damping is employed in modern hard disk drives to reduce tracking errors, they still occur too frequently.
Vibrations from all sources, including drive vibrations, can couple into the atmosphere where they may be perceived as audible noise to users. The cumulative noise from the many drives and fans of a large computer system can produce objectionable noise levels.
U.S. Pat. No. 5,914,855 teaches a drive mounting configuration wherein a disk drive is mounted on a printed circuit card. Each drive card has a plurality of mounting clips compressed onto the edge of the card, with an elastomeric layer disposed between a portion of both a front and a back of the card, the edge of the card, and the mounting clip. The mounting clips are thereupon engaged into a slot of a guide of a card cage to mount the drive, card, elastomeric layer, and clip assembly into the system. U.S. Pat. No. 5,914,855 discloses that the elastomeric layer may be a 0.02-inch (approximately 0.5 millimeter) thick layer of a non-hardening adhesive, and that the elastomeric layer serves to damp and isolate vibrations. The card is illustrated as having card ejectors mounted upon it, as is common with cards slideably installed in a card cage.
It is necessary to ensure that rotating media drives receive adequate cooling airflow. Drives that overheat can destroy themselves, or can fail to read or write correctly while overheatedxe2x80x94in some cases overheated drives can write data at inappropriate locations on the platter such that they will not be able to read that data when they are at a lower temperature. It is also necessary that there be a quick and simple way to assemble a drive into a computer system.
Accordingly, there is a need in the art for improved and alternative devices and methods for damping hard disk drives and other digital media drives.
An assembly for supporting a digital media drive in accordance with this invention includes a mounting structure, such as a secondary plate or runner. The secondary plate is preferably perforated to permit circulation of cooling air. A viscoelastic adhesive member is positioned on one side of the mounting structure to support the digital media drive. The viscoelastic adhesive member need not attach to two sides of the mounting structure. As a result, the digital media drive is substantially isolated from the mounting structure, and both externally and internally induced vibrations are damped, thereby reducing tracking errors. The digital media drive may be, for example, a hard disk drive, a floppy disk drive, a Zip(trademark) drive, a CD-ROM drive, or a DVD-ROM drive.
In another embodiment of this invention, a digital media drive assembly includes first and second guides attached to an enclosure chassis. Also, first and second runners are inserted into the first and second guides. A digital media drive is attached to a mounting plate, and multiple pieces of adhesive viscoelastic material are used to attach the mounting plate and the runners to a secondary plate. As a result, the digital media drive is substantially isolated from the enclosure chassis.
In still other embodiments of this invention, a multi-drive storage device and an electronic system both incorporate the digital media drive assembly described above.
In yet another embodiment of this invention, a digital media drive is mounted on a mounting structure by providing a piece of viscoelastic material and positioning the piece between the digital media drive and the mounting structure so as to support the digital media drive in a spaced-apart relationship with the mounting structure.